Implement env_logger for debug prints

[podhrmic]

Uses env_logger for debug printing. Has the unfortunate effect that no info is printed, suggesting that something else needs to happen. Sharing for awareness.

[spernsteiner]

It sounds like you want env_logger to default to printing info! messages when RUST_LOG is unset? I think there's some fancier way to set up env_logger (instead of env_logger::init(), which uses the library's defaults) that might include a way to do that.